Cartridge for use with an aerosol provision system

ABSTRACT

A cartridge for an aerosol provision system. The cartridge includes an air channel extending from an air inlet to an outlet via an aerosol generation region. The cartridge also includes a heating element for heating liquid from a reservoir to generate aerosol and an aerosol outlet tube. The aerosol outlet tube has a first end and a second end. The first end is proximate to the aerosol generation region and second end is configured to fit inside an air channel seal. The aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end. The cartridge is configured such that air passes from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

PRIORITY CLAIM

The present application is a National Phase entry of PCT Application No. PCT/GB2021/050548, filed Mar. 5, 2021, which claims priority from GB Application No. 2004375.8, filed Mar. 26, 2020, each of which is hereby fully incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to cartridges for use with an aerosol provision system and a system comprising the cartridge.

BACKGROUND

Electronic aerosol provision systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol precursor material, such as a reservoir of a source liquid containing a formulation, typically including nicotine, or a solid material such a tobacco-based product, from which an aerosol is generated for inhalation by a user, for example through heat vaporization. Thus, an aerosol provision system will typically comprise a heating element, e.g. a heating element, arranged to vaporize a portion of precursor material to generate an aerosol in an aerosol generation region of an air channel through the aerosol provision system. As a user inhales on the device and electrical power is supplied to the heating element, air is drawn into the device through one or more inlet holes and along the air channel to the aerosol generation region, where the air mixes with the vaporized precursor material and forms a condensation aerosol. The air drawn through the aerosol generation region continues along the air channel to a mouthpiece opening, carrying some of the aerosol with it, and out through the mouthpiece opening for inhalation by the user.

It is common for aerosol provision systems to comprise a modular assembly, often having two main functional parts, namely an aerosol provision device and disposable/replaceable cartridge part. Typically, the cartridge part will comprise the consumable aerosol precursor material and the heating element (atomizer), while the aerosol provision device part will comprise longer-life items, such as a rechargeable battery, device control circuitry, activation sensors and user interface features. The aerosol provision device may also be referred to as a reusable part or battery section and the replaceable cartridge may also be referred to as a disposable part or cartomizer.

The aerosol provision device and cartridge are mechanically coupled together at an interface for use, for example using a screw thread, bayonet, latched or friction fit fixing. When the aerosol precursor material in a cartridge has been exhausted, or the user wishes to switch to a different cartridge having a different aerosol precursor material, the cartridge may be removed from the aerosol provision device and a replacement cartridge may be attached to the device in its place.

A potential drawback for cartridges containing liquid aerosol precursor (e-liquid) is the risk of leakage. An e-cigarette cartridge will typically have a mechanism, e.g. a capillary wick, for drawing liquid from a liquid reservoir to a heating element located in an air path/channel connecting from an air inlet to an aerosol outlet for the cartridge. Because there is a fluid transport path from the liquid reservoir into the open-air channel through the cartridge, there is a corresponding risk of liquid leaking from the cartridge. Leakage is undesirable both from the perspective of the end user naturally not wanting to get the e-liquid on their hands or other items, and also from a reliability perspective, since leakage from an end of the cartridge connected to the aerosol provision device may damage the aerosol provision device, for example due to corrosion. Some approaches to reduce the risk of leakage may involve restricting the flow of liquid to the heating element, for example by tightly clamping a wick where it enters the air channel, but this can in some scenarios lead to a risk of insufficient liquid being supplied to the heating element (dry-out), which can give rise to overheating and undesirable flavors.

Various approaches are described herein which seek to help address or mitigate some of the issues discussed above.

SUMMARY

The disclosure is defined in the appended claims.

In accordance with some embodiments described herein, there is provided a cartridge for an aerosol provision system comprising the cartridge and an aerosol provision device, the cartridge comprising an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end and wherein the cartridge is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

The aerosol outlet tube may taper inwardly from the first end to a position between the first end and the second end according to a first profile, and the aerosol outlet tube may taper inwardly from the position to the second end according to a second profile, wherein the first profile and the second profile are different.

The first profile may correspond to a first taper angle and the second profile may correspond to a second taper angle.

The first taper angle may be greater than the second taper angle.

The position may be less than 50% of a distance along the aerosol outlet tube from the first end to the second end; for example, the position may be less than 25% of the distance along the aerosol outlet tube from the first end to the second end.

The portion of the air channel from the air channel seal to the outlet may have a substantially constant cross-sectional area.

The cross-sectional area of the portion of the air channel from the air channel seal to the outlet may be less than the cross-sectional area of the second end of the aerosol outlet tube.

The aerosol outlet tube may be made of a plastics material, for example polypropylene.

The air channel seal may be made of silicone.

The cartridge may further comprise a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes the outlet of the cartridge and the interface end includes an interface for coupling the cartridge to the aerosol provision device, wherein the housing part contains the aerosol outlet tube, the air channel seal and the reservoir within the housing part, the reservoir containing liquid for aerosolization, wherein the reservoir at least partially surrounds the aerosol outlet tube and the air channel seal.

In accordance with some embodiments described herein, there is provided an aerosol provision system, the system comprising an air channel extending from an air inlet for the system to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end, and wherein the system is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

In accordance with some embodiments described herein, there is provided a method of generating aerosol from a cartridge for an aerosol provision system, wherein the cartridge comprises an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end, wherein the method comprises passing air through the air channel from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

Thus, it will be appreciated that the combination of air channel, heating element, aerosol outlet tube and air channel seal described herein need not be limited to being located in an cartridge for use with an aerosol provision system, but may for part of an aerosol provision system or component thereof, such as an aerosol delivery device.

The cartridge can be used with an aerosol provision device so as to form an aerosol provision system. The aerosol provision device typically comprises a power source and a controller. In some instances, the aerosol provision device will contain the aerosol-generating component. During operation of the aerosol provision device, the controller will determine that a user has initiated a request for the generation of an aerosol. This could be done via a button on the device, which sends a signal to the controller that the aerosol generator should be powered. Alternatively, a sensor located in or proximal to the airflow pathway could detect airflow through the airflow pathway and convey this detection to the controller. A sensor may also be present in addition to the presence of a button, as the sensor may be used to determine certain usage characteristics, such as airflow, timing of aerosol generation etc.

These aspects and other aspects will be apparent from the following detailed description. In this regard, particular sections of the description are not to be read in isolation from other sections.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:

FIG. 1 schematically represents in perspective view an aerosol provision system comprising a cartridge and aerosol provision device (shown separated) in accordance with certain embodiments of the disclosure;

FIG. 2 schematically represents in exploded perspective view of components of the cartridge of the aerosol provision system of FIG. 1 ;

FIG. 3 is a schematic cut-away view of an alternative example of a cartridge for an aerosol provision system;

FIG. 4 is a schematic cut-away view of a modified example of a cartridge for an aerosol provision system;

FIG. 5 is a schematic cut-away view of the aerosol outlet tube of the cartridge of FIG. 4 ;

FIGS. 6A and 6B are schematic plan views of the aerosol outlet tube of the cartridge of FIG. 4 ;

DETAILED DESCRIPTION OF THE DRAWINGS

Aspects and features of certain examples and embodiments are discussed/described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed/described in detail in the interests of brevity. It will thus be appreciated that aspects and features of articles and systems discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.

The present disclosure relates to aerosol provision systems, which may also be referred to as aerosol provision systems, such as e-cigarettes. Throughout the following description the term “e-cigarette” or “electronic cigarette” may sometimes be used, but it will be appreciated this term may be used interchangeably with aerosol provision system and electronic aerosol provision system.

As noted above, aerosol provision systems (e-cigarettes) often comprise a modular assembly including both a reusable part (aerosol provision device) and a replaceable (disposable) cartridge part. Devices conforming to this type of two-part modular configuration may generally be referred to as two-part devices. It is also common for electronic cigarettes to have a generally elongate shape. For the sake of providing a concrete example, certain embodiments of the disclosure described herein comprise this kind of generally elongate two-part device employing disposable cartridges. However, it will be appreciated the underlying principles described herein may equally be adopted for other electronic cigarette configurations, for example modular devices comprising more than two parts, as devices conforming to other overall shapes, for example based on so-called box-mod high performance devices that typically have a more boxy shape.

As described above, the present disclosure relates to (but it not limited to) cartridges for use with aerosol provision systems, such as e-cigarettes and electronic cigarettes.

FIG. 1 is a schematic perspective view of an example aerosol provision system (e-cigarette) 1 in accordance with certain embodiments of the disclosure. Terms concerning the relative location of various aspects of the electronic cigarette (e.g. terms such as upper, lower, above, below, top, bottom etc.) are used herein with reference to the orientation of the electronic cigarette as shown in FIG. 1 (unless the context indicates otherwise). However, it will be appreciated this is purely for ease of explanation and is not intended to indicate there is any required orientation for the electronic cigarette in use.

The e-cigarette 1 comprises two main components, namely a cartridge 2 and an aerosol provision device 4. The aerosol provision device 4 and the cartridge 2 are shown separated in FIG. 1 , but are coupled together when in use.

The cartridge 2 and aerosol provision device 4 are coupled by establishing a mechanical and electrical connection between them. The specific manner in which the mechanical and electrical connection is established is not of primary significance to the principles described herein and may be established in accordance with conventional techniques, for example based around a screw thread, bayonet, latched or friction-fit mechanical fixing with appropriately arranged electrical contacts/electrodes for establishing the electrical connection between the two parts as appropriate. For example, electronic cigarette 1 represented in FIG. 1 , the cartridge comprises a mouthpiece end 52 and an interface end 54 and is coupled to the aerosol provision device 4 by inserting an interface end portion 6 at the interface end of the cartridge into a corresponding receptacle 8/receiving section of the aerosol provision device 4. The interface end portion 6 of the cartridge is a close fit to be receptacle 8 and includes protrusions 56, which engage with corresponding detents in the interior surface of a receptacle wall 12 defining the receptacle 8 to provide a releasable mechanical engagement between the cartridge 2 and the aerosol provision device 4. An electrical connection is established between the aerosol provision device 4 and the cartridge via a pair of electrical contacts on the bottom of the cartridge (not shown in FIG. 1 ) and corresponding sprung contact pins in the base of the receptacle 8 (not shown in FIG. 1 ). As noted above, the specific manner in which the electrical connection is established is not significant to the principles described herein, and indeed some implementations might not have an electrical connection between the cartridge and an aerosol provision device at all, for example because the transfer of electrical power from the reusable part to the cartridge may be wireless (e.g. based on electromagnetic induction techniques).

The electronic cigarette 1 has a generally elongate shape extending along a longitudinal axis L. When the cartridge is coupled to the aerosol provision device, the overall length of the electronic cigarette in this example (along the longitudinal axis) is around 12.5 cm. The overall length of the aerosol provision device 4 is around 9 cm and the overall length of the cartridge 2 is around 5 cm (i.e. there is around 1.5 cm of overlap between the interface end portion 6 of the cartridge and the receptacle 8 of the aerosol provision device 4 when they are coupled together). The electronic cigarette 1 has a cross-section which is generally oval and which is largest around the middle of the electronic cigarette 1 and tapers in a curved manner towards the ends. The cross-section around the middle of the electronic cigarette has a width of around 2.5 cm and a thickness of around 1.7 cm. The end of the cartridge 2 has a width of around 2 cm and a thickness of around 0.6 mm, whereas the other end of the electronic cigarette 1 has a width of around 2 cm and a thickness of around 1.2 cm. The outer housing of the electronic cigarette 1 is in this example is formed from a plastics material. It will be appreciated the specific size and shape of the electronic cigarette and the material from which it is made is not of primary significance to the principles described herein and may be different in different implementations. That is to say, the principles described herein may equally be adopted for electronic cigarettes having different sizes, shapes and/or materials.

The aerosol provision device 4 may in accordance with certain embodiments of the disclosure be broadly conventional in terms of its functionality and general construction techniques. In the example of FIG. 1 , the aerosol provision device 4 comprises a plastic outer housing 10 including the receptacle wall 12 that defines the receptacle 8 for receiving the end of the cartridge as noted above. The outer housing 10 of the aerosol provision device 4 in this example has a generally oval cross section conforming to the shape and size of the cartridge 2 at their interface to provide a smooth transition between the two parts. The receptacle 8 and the end portion 6 of the cartridge 2 are symmetric when rotated through 180° so the cartridge can be inserted into the aerosol provision device in two different orientations. The receptacle wall 12 includes two aerosol provision device air inlet openings 14 (i.e. holes in the wall). These openings 14 are positioned to align with an air inlet 50 for the cartridge when the cartridge is coupled to the aerosol provision device. A different one of the openings 14 aligns with the air inlet 50 of the cartridge in the different orientations. It will be appreciated some implementations may not have any degree of rotational symmetry such that the cartridge is couplable to the aerosol provision device in only one orientation while other implementations may have a higher degree of rotational symmetry such that the cartridge is couplable to the aerosol provision device in more orientations.

The aerosol provision device further comprises a battery 16 for providing operating power for the electronic cigarette, control circuitry 18 for controlling and monitoring the operation of the electronic cigarette, a user input button 20, an indicator light 22, and a charging port 24.

The battery 16 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods. The battery 16 may be recharged through the charging port 24, which may, for example, comprise a USB connector.

The input button 20 in this example is a conventional mechanical button, for example comprising a sprung mounted component, which may be pressed by a user to establish an electrical contact in underlying circuitry. In this regard, the input button may be considered an input device for detecting user input, e.g. to trigger aerosol generation, and the specific manner in which the button is implemented is not significant. For example, other forms of mechanical button or touch-sensitive button (e.g. based on capacitive or optical sensing techniques) may be used in other implementations, or there may be no button and the device may rely on a puff detector for triggering aerosol generation.

The indicator light 22 is provided to give a user with a visual indication of various characteristics associated with the electronic cigarette, for example, an indication of an operating state (e.g. on/off/standby), and other characteristics, such as battery life or fault conditions. Different characteristics may, for example, be indicated through different colors and/or different flash sequences in accordance with generally conventional techniques.

The control circuitry 18 is suitably configured/programmed to control the operation of the electronic cigarette to provide conventional operating functions in line with the established techniques for controlling electronic cigarettes. The control circuitry (processor circuitry) 18 may be considered to logically comprise various sub-units/circuitry elements associated with different aspects of the electronic cigarette's operation. For example, depending on the functionality provided in different implementations, the control circuitry 18 may comprises power supply control circuitry for controlling the supply of power from the battery to the cartridge in response to user input, user programming circuitry for establishing configuration settings (e.g. user-defined power settings) in response to user input, as well as other functional units/circuitry associated functionality in accordance with the principles described herein and conventional operating aspects of electronic cigarettes, such as indicator light display driving circuitry and user input detection circuitry. It will be appreciated the functionality of the control circuitry 18 can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and/or one or more suitably configured application-specific integrated circuit(s)/circuitry/chip(s)/chipset(s) configured to provide the desired functionality.

FIG. 2 is an exploded schematic perspective view of the cartridge 2 (exploded along the longitudinal axis L). The cartridge 2 comprises a housing part 32, an air channel seal 34, a dividing wall element 36, an aerosol outlet tube 38, a heating element 40, a liquid transport element 42, a plug 44, and an end cap 48 with contact electrodes 46.

FIG. 3 is a schematic cut-away view of an alternative example of a cartridge 2 for an aerosol provision system 1, where the same reference signs have been used for like elements between the cartridge 2 illustrated in FIG. 2 and the cartridge 2 illustrated in FIG. 3 . The cartridge 2 illustrated in FIG. 3 also comprises a housing part 32, an air channel seal 34, a heating element 40, a liquid transport element 42, a plug 44, and an end cap 48 with contact electrodes 46. The cartridge 2 illustrated in FIG. 3 , however, has an aerosol outlet tube 38, which also acts as a dividing wall. In other words, the aerosol outlet tube 38 in FIG. 3 is a single component integrating the design and functionality of both the dividing wall element 36 and the aerosol outlet tube 38 illustrated in FIG. 2 .

In both the examples in FIG. 2 and FIG. 3 , the housing part 32 comprises a housing outer wall 64 and a housing inner tube 62 which are formed from a single molding of polypropylene. The housing outer wall 64 defines the external appearance of the cartridge 2 and the housing inner tube 62 defines a part an air channel through the cartridge 2. The housing part is open at the interface end 54 of the cartridge and closed at the mouthpiece end 52 of the cartridge except for a mouthpiece opening/aerosol outlet 60 in fluid communication with the housing inner tube 62. The housing part 32 includes an opening in a sidewall, which provides the air inlet 50 for the cartridge. The air inlet 50 in both examples has an area of around 2 mm². The housing part 32 includes the protrusions 56 discussed above which engage with corresponding detents in the interior surface of the receptacle wall 12 defining the receptacle 8 to provide a releasable mechanical engagement between the cartridge and the control unit. The inner surface of the outer wall 64 of the housing part includes further protrusions 66 which act to provide an abutment stop for locating the plug 44 and the end cap 48 along the longitudinal axis L when the cartridge is assembled.

The air channel seal 34 in both examples is a silicone molding generally in the form of a tube having a through hole 80. The outer wall of the air channel seal 34 includes circumferential ridges 84 and an upper collar 82. The inner wall of the air channel seal 34 also includes circumferential ridges 86. When the cartridge is assembled the air channel seal 34 is mounted to the housing inner tube 62 with an end of the housing inner tube 62 extending partly into the through hole 80 of the air channel seal 34. The through hole 80 in the air channel seal has a diameter of around 5.8 mm in its relaxed state whereas the end of the housing inner tube 62 has a diameter of around 6.2 mm so that a seal is formed when the air channel seal 34 is stretched to accommodate the housing inner tube 62. This seal is facilitated by the 86 ridges on the inner surface of the air channel seal 34.

In the example in FIG. 2 , the outlet tube 38 comprises a tubular section of ANSI 304 stainless steel with an internal diameter of around 8.6 mm and a wall thickness of around 0.2 mm, whilst the outlet tube 38 the example in FIG. 3 is made of polypropylene. In both examples, the bottom end of the outlet tube 38 includes a pair of diametrically opposing slots 88 with an end of each slot having a semi-circular recess 90. When the cartridge 2 is assembled, the outlet tube 38 mounts to the outer surface of the air channel seal 34. The outer diameter of the air channel seal 34 is around 9.0 mm in its relaxed state so that a seal is formed when the air channel seal 34 is compressed to fit inside the outlet tube 38. This seal is facilitated by the ridges 84 on the outer surface of the air channel seal 34. The collar 82 on the air channel seal 34 provides a stop for the outlet tube 38.

The liquid transport element 42 comprises a capillary wick and the heating element 40 comprises a resistance wire heater wound around the capillary wick. For ease of illustration, the liquid transport element 42 and the heating element 40 have been omitted from FIG. 3 . In addition to the portion of the resistance wire wound around the capillary wick, the heating element comprises electrical leads 41 which pass through holes in the plug 44 to contact electrodes 46 mounted to the end cap 54 to allow power to be supplied to the heating element via the electrical interface the established when the cartridge is connected to a control unit. The heating element leads 41 may comprise the same material as the resistance wire wound around the capillary wick, or may comprise a different material (e.g. lower-resistance material) connected to the resistance wire wound around the capillary wick. In both examples, the heater coil 40 comprises a nickel iron alloy wire and the wick 42 comprises a glass fiber bundle. The heating element and liquid transport element may be provided in accordance with any conventional techniques and is may comprise different forms and/or different materials. For example, in some implementations, the wick may comprise fibrous or solid a ceramic material and the heater may comprise a different alloy. In other examples, the heater and wick may be combined, for example in the form of a porous and a resistive material. More generally, it will be appreciated the specific nature liquid transport element and heating element is not of primary significance to the principles described herein.

When the cartridge is assembled, the wick 42 is received in the semi-circular recesses 90 of the outlet tube 38 so that a central portion of the wick about which the heating coil is would is inside the outlet tube while end portions of the wick are outside the outlet tube 38.

The plug 44 in the examples illustrated in FIG. 2 and FIG. 3 comprises a single molding of silicone, which may be resilient. The plug comprises a base part 100 with a wall 102 extending upwardly therefrom (i.e. towards the mouthpiece end of the cartridge).

The outer portion of the wall 102 of the plug 44 conforms to an inner surface of the housing part 32 so that when the cartridge is assembled the plug in 44 forms a seal with the housing part 32. The inner portion of the wall 104 of the plug 44 conforms to an inner surface of the outlet tube 38 so that when the cartridge is assembled the plug 44 also forms a seal with the outlet tube 38.

The end cap 48 comprises a polypropylene molding with a pair of gold-plated copper electrode posts 46 mounted therein. The ends of the electrode posts 46 on the bottom side of the end cap 48 are close to flush with the interface end 54 of the cartridge provided by the end cap 48. These are the parts of the electrodes to which correspondingly aligned sprung contacts in the control unit connect when the cartridge is assembled and connected to the control unit. The ends of the electrode posts on the inside of the cartridge extend away from the end cap 48 and into the holes in the plug 44 through which the contact leads 41 pass. The electrode posts 46 are slightly oversized relative to the holes and include a chamfer at their upper ends to facilitate insertion into the holes in the plug 44 where they are maintained in pressed contact with the contact leads for the heating element 40 by virtue of the plug 44.

In the example illustrated in FIG. 2 , the dividing wall element 36 comprises a single molding of polypropylene and includes a dividing wall 130. The dividing wall element 36 has a central opening through which the outlet tube 38 passes (i.e. the dividing wall 130 is arranged around the outlet tube 38). When the cartridge is assembled, the upper surface of the outer wall of the plug 44 engages with the lower surface of the dividing wall 130, and the upper surface of the dividing wall 130 in turn engages with the projections 66 on the inner surface of the outer wall 64 of the housing part 32. Thus, the dividing wall 130 prevents the plug from being pushed too far into the housing part 32. In other words, the dividing wall 130 is fixedly located along the longitudinal axis of the cartridge by the protrusions 66 in the housing part and so provides the plug with a fixed surface to push against. The dividing wall element 36 also comprises a first pair of opposing projections/tongues 134, which extend from the dividing wall 130 in the direction towards the interface end of the cartridge. The pair of opposing projections 134 engage with corresponding recesses on an inner surface of the outer wall of the plug 44. The projections 134 from the dividing wall 130 further provide a pair of cradle sections 136 configured to engage with corresponding ones of the cradle sections in the plug 44 when the cartridge 2 is assembled to further define the opening through which the liquid transport element 42 passes.

In the example illustrated in FIG. 3 , the dividing wall 130 is incorporated into the outlet tube 38. In other words, the outlet tube 38 has an outwardly extending flange 130, which acts as a dividing wall, thereby removing the need for a separate dividing wall element 36 since the functionality of the dividing wall element is incorporated into the outlet tube 38. In the same way as described above, when the cartridge 2 is assembled, the upper surface of the outer wall of the plug 44 engages with the lower surface of the dividing wall 130, and the upper surface of the dividing wall 130 in turn engages with the projections 66 on the inner surface of the outer wall 64 of the housing part 32.

In both the examples illustrated in FIGS. 2 and 3 , when the cartridge 2 is assembled, a reservoir 63 for liquid is formed by the space outside the inner tube 62 of the housing 32 and inside the outer wall 64 of the housing 32. This may be filled during manufacture, for example through a filling hole, which is then sealed, or by other means. The specific nature of the liquid, for example in terms of its composition, is not of primary significance to the principles described herein, and in general any conventional liquid of the type normally used in electronic cigarettes may be used. The reservoir 63 is closed at the interface end of the cartridge by the plug 44. The reservoir includes a first region above the dividing wall 130 and a second region below the dividing wall 130 within the space formed between the aerosol outlet tube 38 and the plug 44. The liquid transport element (capillary wick) 42 passes through openings in the wall of the outlet tube 38 provided by the semi-circular recesses 90. Thus, the ends of the liquid transport element 42 extend into the second region of the reservoir 63 from which they draw liquid to the heating element 40 for subsequent vaporization.

In normal use, the cartridge 2 is coupled to the control unit 4 and the control unit activated to supply power to the cartridge via the contact electrodes 46 in the end cap 48. Power then passes through the connection leads 41 to the heating element 40. The heating element is thus electrically heated and so vaporizes a portion of the liquid from the liquid transport element in the vicinity of the heating element 40. This generates aerosol in an aerosol generation region, which includes the heating element. Liquid that is vaporized from the liquid transport element is replaced by more liquid drawn from the reservoir by capillary action. While the heating element 40 is activated, a user inhales on the mouthpiece end 52 of the cartridge 2. This causes air to be drawn through whichever control unit air inlet 14 aligns with the air inlet 50 of the cartridge (which will depend on the orientation in which the cartridge was inserted into the control unit receptacle 8). Air then enters the cartridge 2 through the air inlet 50 before entering the aerosol generation region surrounding the heating element 40. The incoming air mixes with aerosol generated from the heating element 40 to form a condensation aerosol, which is then drawn along the outlet tube 38 and the housing part inner 62 before exiting through the mouthpiece outlet/aerosol outlet 60 for user inhalation.

FIG. 4 is a schematic cut-away view of a modified example of a cartridge 2 for an aerosol provision system 1, where the same reference signs have been used for like elements between the cartridge 2 illustrated in FIGS. 2 and 3 and the cartridge 2 illustrated in FIG. 4 . As per the cartridge illustrated in FIG. 3 , the cartridge 2 illustrated in FIG. 4 comprises a housing part 32, an air channel seal 34, a heating element 40, a liquid transport element 42, a plug 44, an end cap 48 with contact electrodes 46, and an aerosol outlet tube 38 which also acts as a dividing wall. In other words, the aerosol outlet tube 38 in FIG. 4 also has an integrated dividing wall 130.

In the example illustrated in FIG. 4 , an air channel is defined as extending from the air inlet 50 for the cartridge 2 to the outlet 60. The air channel extends through the aerosol generation region 43 in which the heating element 40 is located. As described above, the heating element 40 heats liquid from the reservoir 63 to generate aerosol in the aerosol generation region 43. The cartridge 2 is configured such that air passing through the air channel passes from the air inlet 50, into the aerosol generating region 43, through the aerosol outlet tube 38, past the air channel seal 34 and then out from the outlet 60.

The aerosol outlet tube 38 has a first end 38 a proximate to the aerosol generation region 43 and a second end 38 b configured to fit inside the air channel seal 34. The air channel seal 34 illustrated in FIG. 4 has an inner flange 81 and an outer flange 83. The outer flange 83 is located outside the inner flange 81, in other words a larger radial distance away from the longitudinal axis L. This forms a slot between the inner flange 81 and the outer flange 83. The slot is a size and shape to receive the second end 38 b of the aerosol outlet tube 38. In other words, the second end 38 b of the aerosol outlet tube 38 is configured to fit inside the air channel seal 34, such that when the cartridge 2 is assembled, a compression fit is achieved between the second end 38 b of the outlet tube 38, the inner flange 81 and the outer flange 83 of the air channel seal 34. Therefore, when the cartridge is assembled 2, the inner flange 81 of the air channel seal 34 is located inside the outlet tube 38 (in other words closer to the longitudinal axis L), and the outlet tube 38 is located inside the outer flange 83 of the air channel seal 34 (in other words further from the longitudinal axis L).

The aerosol outlet tube 38 tapers inwardly from the first end 38 a to the second end 38 b such that a cross-sectional area of the second end 38 b is less than a cross-sectional area of the first end 38 a. This is shown in more detail in FIGS. 5 and 6 .

FIG. 5 is a schematic cut-away view of the aerosol outlet tube 38 of the cartridge 2 of FIG. 4 whilst FIGS. 6A and 6B are schematic plan views of the aerosol outlet tube of the cartridge of FIG. 4 . As illustrated in FIG. 5 , the aerosol outlet tube 38 tapers inwardly from the first end 38 a to the second end 38 b. In other words, the walls of the aerosol outlet tube 38 at the second end 38 b of the aerosol outlet tube 38 are closer to the longitudinal axis L of the cartridge than the walls of the aerosol outlet tube 38 at the first end 38 a of the aerosol outlet tube 38. In between the first end 38 a and the second end 38 b of the aerosol outlet tube 38, the walls of the aerosol outlet tube 38 taper inwards according to a profile. In the example illustrated in FIGS. 4 and 5 the profile corresponds to two linear profiles, but in other examples the profile may correspond to a single linear profile, in other words a single straight line between the first end 38 a and the second end 38 b of the aerosol outlet tube 38, or the profile may be curved, stepped, or any other shape which results in the cross-sectional area of the second end 38 b being less than the cross-sectional area of the first end 38 a. In the example illustrated in FIGS. 4 and 5 , the taper is symmetrical about the longitudinal axis L such that the cross-sections of the first end 38 a and the second end 38 b of the aerosol outlet tube 38 are centered on the longitudinal axis L, but this is not essential, and any tapering profile which results in the cross-sectional area of the second end 38 b being less than the cross-sectional area of the first end 38 a may be used.

Whilst it can be seen in FIG. 5 that the first end 38 a of the aerosol outlet tube 38 does not correspond to the bottom 38 d of the aerosol outlet tube, it will be appreciated that when the aerosol outlet tube 38 is assembled into the cartridge 2 as illustrated in FIG. 4 , the heating element 40 and the liquid transport element 42 pass between the semi-circular recesses 90 such that the heating element 40 and the liquid transport element 42 are located between the first end 38 a of the aerosol outlet tube 38 and the bottom 38 d of the aerosol outlet tube 38. This portion of the aerosol outlet tube 38 between the first end 38 a and the bottom 38 d of the aerosol outlet tube 38 therefore corresponds to, or in other words is located inside, the aerosol generation region 43 of the cartridge 2. The first end 38 a of the aerosol outlet tube 38 therefore corresponds to the portion of the aerosol outlet tube 38 proximate to the aerosol generation region 43 as described above. In other words, the first end 38 a of the aerosol outlet tube 38 corresponds to the portion of the aerosol outlet tube 38 immediately following the aerosol generation region 43 along the air channel in the direction of air flow from the air inlet 50 to the outlet 60.

FIG. 6A is a plan view of the bottom of the aerosol outlet tube 38, in other words in the viewing direction from the end cap 48 to the mouthpiece 52 of the assembled cartridge 2 along the longitudinal axis L, whilst FIG. 6B is a plan view of the top of the aerosol outlet tube 38, in other words in the viewing direction from mouthpiece 52 to the end cap 48 of the assembled cartridge 2 along the longitudinal axis L. The shaded portion in the center of FIG. 6A corresponds to the cross-sectional area of the first end 38 a of the aerosol outlet tube 38 whilst the shaded portion in the center of FIG. 6B corresponds to the cross-sectional area of the second end 38 b of the aerosol outlet tube 38. As can be seen from FIGS. 6A and 6B, due to the inward taper of the aerosol outlet tube 38 from the first end 38 a to the second end 38 b, the cross-sectional area of the second end 38 b, indicated by the shaded region in FIG. 6B, is less than the cross-sectional area of the first end 38 a, indicated by the shaded region in FIG. 6A.

As shown in FIG. 5 , the aerosol outlet tube 38 tapers inwardly from the first end 38 a to a position 38 c between the first end and the second end 38 b. The aerosol outlet tube 38 then tapers inwardly to the second end 38 b from the position 38 c between the first end and the second end 38 b. For ease of illustration and explanation, the relative positions of the first end 38 a, the position 38 c and the second end 38 b of the aerosol outlet tube 38 along the central axis L of the cartridge are indicated by solid horizontal lines in FIG. 5 .

The aerosol outlet tube 38 tapers inwardly from the first end 38 a to the position 38 c between the first end 38 a and the second end 38 b according to a first profile and the aerosol outlet tube 38 tapers inwardly from the position 38 c to the second end 38 b according to a second profile. The first profile and the second profile are different in the example illustrated in FIG. 5 . In this example, the first profile and the second profile are both linear profiles, but the angle of the wall of the aerosol outlet tube 38 between the first end 38 a and the position 38 c relative to the longitudinal axis L is different to the angle of the wall of the aerosol outlet tube 38 between the position 38 c and the second end 38 b relative to the longitudinal axis L. In other words, the first profile corresponds to a first taper angle θ and the second profile corresponds to a second taper angle φ, where a taper angle is defined as the angle of the wall relative to the longitudinal axis L of the cartridge 2. As illustrated in FIG. 5 , the first taper angle θ is greater than the second taper angle φ such that the change in cross-sectional area of the aerosol outlet tube 38 between the first end 38 a and the position 38 c is greater than the change in cross-sectional area of the aerosol outlet tube 38 between the position 38 c and the second end 38 b. In other words, the cross-sectional area of the aerosol outlet tube 38 at the position 38 c is closer in magnitude to the cross-sectional area of the aerosol outlet tube 38 at the second end 38 c than the first end 38 a. The first taper angle θ may be between 30° and 60°, for example 45°, whilst the second taper angle φ may be between 0.5° and 10°, for example 2°.

Whilst in the example illustrated in FIG. 5 , the first profile and the second profile are both linear profiles; in other examples, the first profile and the second profile may be other shapes. For example, the first profile may be curved, such as a parabolic or catenary curve whilst the second profile is linear, or vice versa. In other examples, both the first profile and the second profile are curved, but the shape of the curve defining the first profile and the curve of the second profile is different.

As illustrated in FIG. 5 , the position 38 c is less than 50% of a distance along the aerosol outlet tube 38 from the first end 38 a of the aerosol outlet tube to the second end 38 b of the aerosol outlet tube 38, where the distance may be considered to be the distance between the first end 38 a of the aerosol outlet tube and the second end 38 b of the aerosol outlet tube 38 the along the longitudinal axis L of the cartridge 2. In other words, the position 38 c is closer to the first end 38 a of the aerosol outlet tube than to the second end 38 b of the aerosol outlet tube 38. In some examples, such as the example illustrated in FIG. 5 , the position 38 c is less than 25% of the distance along the aerosol outlet tube 38 from the first end 38 a to the second end 38 b.

As can be seen by comparing FIGS. 3 and 4 , the tapered profile of the aerosol outlet tube 38 illustrated in FIG. 4 increases the volume of the reservoir 63 in the region around the aerosol outlet tube 38 compared to the straight design of aerosol outlet tube 38 illustrated in FIG. 3 . The total volume of the reservoir 63 in the cartridge 2 with the tapered profile of the aerosol outlet tube 38 illustrated in FIG. 4 is 2.064 ml whilst the total volume of the reservoir 63 in the cartridge 2 with the straight profile of the aerosol outlet tube 38 illustrated in FIG. 3 is 2.039 ml. The tapered profile of the aerosol outlet tube 38 therefore increases the volume of the reservoir 63 in the cartridge 2 without changing the external shape or appearance of the cartridge 2. An increased volume of reservoir allows more liquid to be stored in the cartridge 2, which therefore allows more usage out of each cartridge 2 before the liquid is exhausted from the cartridge 2 and the cartridge 2 needs to be replaced. As illustrated in FIGS. 6A and 6B, the dividing wall 130 of the aerosol outlet tube 38 is in the form of an annular band around the air channel and comprises four fluid communication openings 150 located in respective quadrants of the band. The fluid communication openings 150 allow liquid stored in the reservoir 63 to flow through the dividing wall 130 and between the first region and the second region of the reservoir 63.

Referring again to FIG. 4 , the housing part 32 has a mouthpiece end 52 and an interface end 54. The mouthpiece end 52 includes the outlet 60 of the cartridge 2 and the interface end 54 includes an interface for coupling the cartridge 2 to the aerosol provision device 4. The housing part 32 contains the aerosol outlet tube 38, the air channel seal 34. The reservoir 63 is also contained within the housing part 32, and the reservoir 63 contains liquid for aerosolization. As can be seen in FIG. 4 , the reservoir 63 at least partially surrounds the aerosol outlet tube 38 and the air channel seal 34. In other words, the reservoir 63 is located outside, or further away from the longitudinal axis L than the aerosol outlet tube 38 and the air channel seal 34. This results in the air channel extending through the reservoir. As illustrated in FIG. 4 , this corresponds to the air channel passing up the center of the housing part 32, with the reservoir 63 located outside of the central portion of the housing part 32. This not essential, however, and the air channel may not be located in the center of the housing part 32.

In the modified example illustrated in FIG. 4 , the housing inner tube 62 extends from the air channel seal 34 to outlet 60, and therefore also defines a portion the air channel through the cartridge 2. This portion of the air channel from the air channel seal 34 to the outlet 60 has a substantially constant cross-sectional area. This ensures a smooth or steady flow of aerosol through the air channel, reducing turbulence within the air channel and reducing the likelihood of the aerosol condensing inside the housing inner tube 62.

An air gap 70 surrounds the housing inner tube 62 between the housing inner tube 62 and the reservoir 63. This acts as a layer of insulation between the housing inner tube 62 and the reservoir 63 and further reduces the likelihood of condensates forming on the walls of the housing inner tube 62 inside the air channel.

As illustrated in FIG. 4 , the cross-sectional area of the housing inner tube 62 (in other words, the portion of the air channel from the air channel seal 34 to the outlet 60) is less than the cross-sectional area of the second end 38 b of the aerosol outlet tube 38. This acts as a restrictor in the air channel, thereby increasing the draw strength required by the user in order for the user to draw air through the air channel from the air inlet 50 to the air outlet 60. The cross-sectional area of the air channel in the housing inner tube 62 is also substantially the same as the cross-sectional area of the air channel in the air channel seal 34, thereby providing a smooth transition in the air channel between the air channel seal 34 and the housing inner tube 62. The cross-sectional area of the air channel in the air channel seal 34 is less than the cross-sectional area of the second end 38 b of the aerosol outlet tube 38. This not only combines with the housing inner tube 62 to act as a restrictor in the air channel, but also facilitates insertion of the inner flange 81 of the air channel seal 34 into the aerosol outlet tube 38 when the cartridge 2 is assembled as described above, allowing the inner flange 81 of the air channel seal 34 into be located the aerosol outlet tube 38.

The aerosol outlet tube 38 in this modified example illustrated in FIG. 4 is made of a plastics material, for example polypropylene or polyethylene. This reduces the cost of manufacturing the aerosol outlet tube 38 in the modified example illustrated in FIG. 4 compared to the example illustrated in FIG. 2 , as the aerosol outlet tube 38 illustrated in FIG. 2 is made from a stainless steel which has a higher material cost. Additionally, the cartridge 2 illustrated in FIGS. 3 and 4 is made of fewer parts than the cartridge 2 illustrated in FIG. 2 , since the function of the separate dividing wall element 36 of the cartridge 2 illustrated in FIG. 2 in incorporated into the aerosol outlet tube 38 of the cartridge illustrated in FIGS. 3 and 4 , further reducing the manufacturing costs.

The air channel seal 34 of the modified example illustrated in FIG. 4 is made of silicone and is configured to rest against the housing inner tube 62. In other words, the air channel seal 34 touches the housing inner tube 62 but is not fixed to the housing inner tube 62. The tapered shape of the aerosol outlet tube 38 allows the aerosol outlet tube 38 and the air channel seal 34 to deflect downwards. In other words, the aerosol outlet tube 38 and the air channel seal 34 are able to deflect away from the housing inner tube 62 and towards the aerosol generation region 43 along the longitudinal axis L of the cartridge.

As described above, there is an air gap 70 surrounding the housing inner tube 62 between the housing inner tube 62 and the reservoir 63. As the aerosol outlet tube 38 and the air channel seal 34 deflect away from the housing inner tube 62, an opening into the air gap 70 is created between the air channel seal 34 and the housing inner tube 62, allowing air to pass between the air channel and the air gap 70. Typically, the air pressure in the air gap 70 is greater than the ambient pressure outside the cartridge 2. As the user draws on the mouthpiece 52, air is drawn along the air channel from the air inlet 50 to the air outlet 60. The air is drawn through the aerosol outlet tube 38 and the air channel seal 34, where the cross-sectional area decreases from the first end 38 a of the aerosol outlet tube 38 to the second end 38 b of the aerosol outlet tube 38 and, as described above, the cross-sectional area of the air channel through the air channel seal 34 and the housing inner tube 62 is less than the cross-sectional area of the second end 38 b of the aerosol outlet tube 38. As a result, the speed of the aerosol through the air channel increases as the aerosol passes through the aerosol outlet tube 38, the air channel seal 34 and the housing inner tube 62. In turn, the pressure in the air channel decreases, causing the air channel seal 34 to be drawn towards and to rest against the housing inner tube 62, closing the opening into the air gap 70. When the user stops drawing on the mouthpiece 52 or removes their mouth from the mouthpiece end, the pressure in the air gap 70 is greater than the pressure in the housing inner tube 62 and the air channel seal 34. This pressure force deflects the aerosol outlet tube 38 and the air channel seal 34 away from the housing inner tube 62, creating the opening into the air gap 70, which is turn, allows air to pass between the air gap 70 and the air channel, thereby equalizing the pressure between the air gap 70 and the air channel. This prevents any buildup of pressure within the cartridge 2 and thereby ensures that the geometry of the air channel is maintained, preventing any additional constrictions or restrictions in the air channel which may increase the draw strength required by the user and negatively impact the user experience. The ability of the aerosol outlet tube 38 and the air channel seal 34 to deflect and create the opening is facilitated by the inwards tapering of the aerosol outlet tube 38 from the first end 38 a to the second 38 b. The ability of the aerosol outlet tube 38 and the air channel seal 34 to deflect and create the opening is further facilitated by manufacturing the aerosol outlet tube 38 from a plastics material, such as polypropylene, as this provides a flexible aerosol outlet tube 38 that can repeatedly deflect without undergoing any permanent deformation.

Thus, there has been described a cartridge for an aerosol provision system comprising the cartridge and an aerosol provision device, wherein the cartridge an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal, wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end, and wherein the cartridge is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

As has been described within, in some examples an aerosol provision system comprises an air channel extending from an air inlet for the system to an outlet via an aerosol generation region, a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region, an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal. The aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end. The system is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol-generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.

In such an aerosol provision system, the air channel, the heating element, the aerosol outlet tube and the air channel seal may form part of a cartridge as described above. Alternatively, the air channel, the heating element, the aerosol outlet tube and the air channel seal may form part of an aerosol delivery device for use with a cartridge. In this case, the air channel, the heating element, the aerosol outlet tube and the air channel seal may be are characterized according to the features described herein.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future. 

1. A cartridge for an aerosol provision system comprising the cartridge and an aerosol provision device, wherein the cartridge comprises: an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region; a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region; an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal; wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end; and wherein the cartridge is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.
 2. The cartridge of claim 1, wherein the aerosol outlet tube tapers inwardly from the first end to a position between the first end and the second end according to a first profile, and the aerosol outlet tube tapers inwardly from the position to the second end according to a second profile, wherein the first profile and the second profile are different.
 3. The cartridge of claim 2, wherein the first profile corresponds to a first taper angle and the second profile corresponds to a second taper angle.
 4. The cartridge of claim 3, wherein the first taper angle is greater than the second taper angle.
 5. The cartridge of claim 2, wherein the position is less than 50% of a distance along the aerosol outlet tube from the first end to the second end.
 6. The cartridge of claim 5, wherein the position is less than 25% of the distance along the aerosol outlet tube from the first end to the second end.
 7. The cartridge of claim 1, wherein the portion of the air channel from the air channel seal to the outlet has a substantially constant cross-sectional area.
 8. The cartridge of claim 7, where the cross-sectional area of the portion of the air channel from the air channel seal to the outlet is less than the cross-sectional area of the second end of the aerosol outlet tube.
 9. The cartridge of claim 1, wherein the aerosol outlet tube is made of a plastics material.
 10. The cartridge of claim 9, wherein the plastics material is polypropylene.
 11. The cartridge of claim 1, wherein the air channel seal is made of silicone.
 12. The cartridge of claim 1, further comprising: a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes the outlet of the cartridge and the interface end includes an interface for coupling the cartridge to the aerosol provision device; wherein the housing part contains the aerosol outlet tube, the air channel seal and the reservoir within the housing part, the reservoir containing liquid for aerosolization, wherein the reservoir at least partially surrounds the aerosol outlet tube and the air channel seal.
 13. An aerosol provision system, the system comprising: an air channel extending from an air inlet for the system to an outlet via an aerosol generation region; a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region; an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal; wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end; and wherein the system is configured such that air passing through the air channel is configured to pass from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet.
 14. The aerosol provision system according to claim 13, wherein the aerosol provision system comprises a cartridge and an aerosol provision device, and the air channel, the heating element, the aerosol outlet tube and the air channel seal form part of the cartridge, as defined in claim
 1. 15. The aerosol provision system according to claim 13, wherein the aerosol provision system comprises a cartridge and an aerosol provision device, and the air channel, the heating element, the aerosol outlet tube and the air channel seal form part of the aerosol delivery device for use with the cartridge.
 16. (canceled)
 17. A method of generating aerosol from a cartridge for an aerosol provision system, wherein the cartridge comprises: an air channel extending from an air inlet for the cartridge to an outlet via an aerosol generation region; a heating element for heating liquid from a reservoir to generate aerosol in the aerosol generation region; an aerosol outlet tube having a first end and a second end, the first end proximate to the aerosol generation region and second end configured to fit inside an air channel seal; wherein the aerosol outlet tube tapers inwardly from the first end to the second end such that a cross-sectional area of the second end is less than a cross-sectional area of the first end; and wherein the method comprises passing air through the air channel from the air inlet, into the aerosol generating region, through the aerosol outlet tube, past the air channel seal and then out from the outlet. 